—Sorry, I'm late.

—It's OK. However, you________come to the company today, for it is Saturday. [ ]

A. couldn't have  

B. needn't have

C. wouldn't  

D. couldn't

关于咽鼓管的描述正确的是（）

A.连通鼓室与口咽部

B.外侧份为软骨部，内侧份为骨部

C.外端开口于鼓室颈静脉壁

D.内覆有黏膜

E.内端开口于咽隐窝